In a conventional shelf apparatus, pillars arranged at the right and left each have a rectangular sectional shape and are made of, for example, steel. In at least front surfaces of the pillars, multiple engagement holes are formed in two columns at the right and left. The engagement holes allow a bracket for supporting a side end portion of a shelf board to be engaged therewith. The bracket which extends in a front-rear direction has, at an upper end, a horizontal piece which is oriented inward between the right and left pillars and used for supporting the shelf board, and has, at a rear end, three engagement claws which extend downward and can be engaged with the engagement holes of the corresponding pillar (for example, see Patent Document 1).
A conventional product support apparatus includes: a cylindrical fixture member having a right-prism hollow hole which opens at an upper end and has a rectangular sectional shape, the fixture member being fixed to a pillar with the hollow hole inclined; and a load support member having a load receiving portion and an engagement portion which is provided contiguously to a rear end of the load receiving portion with a predetermined inclination angle provided therebetween and is formed in a rectangular right-prism shape having a sectional area smaller than that of the hollow hole by a minute dimension so that the engagement portion can be inserted into the hollow hole of the fixture member. In order to prevent an end (rear) surface of the engagement portion from contacting with the fixture member when the engagement portion is inserted into the hollow hole, the length of the engagement portion is set to be shorter than the depth dimension of the hollow hole. After the engagement portion of the load support member is straightly inserted in an extractable manner into the hollow hole of the fixture member from its upper end, by the own weight of the load support member, two parts of an end (rear) upper edge and a base (front) lower edge of the engagement portion are caused to contact with a hollow-hole surface of the fixture member so as to be held therein, whereby the load support member is engaged with the fixture member (for example, see Patent Document 2).